Final answer:
Rat pups with high levels of maternal care demonstrate better emotional regulation and less amygdala activation, while those with negative early experiences show increased amygdala activation and depressive-like symptoms in adolescence.
Step-by-step explanation:
Pups that experience high levels of licking, grooming, and arched-back nursing (LG-ABN) display different developmental outcomes compared to those who do not receive such care. Research shows that negative early life experiences, such as abusive treatment or insufficient care, can lead to alterations in the function of the amygdala. These changes are associated with depressive-like symptoms and increased amygdala activation during adolescence. Conversely, positive maternal interactions can mitigate the learning of fear responses to certain stimuli. In the presence of the mother, for instance, rat pups exhibited a preference rather than an aversion to an odor paired with an electrical shock, showing no increase in amygdala activation. This sheds light on the importance of early life experience in shaping the neurological and behavioral development of offspring.